Bulk materials are often transported in containers such as large flexible bags. Such material may include cement, plastic, grains, and the like.
One example of a flexible bulk bag is that disclosed in U.S. Pat. No. 5,785,175. This particular bulk bag is especially adapted for lifting by the forks or tines of a fork lift. The bulk bag has a base, a plurality of sidewalls, and various forms of reinforcing members which add strength to the bulk bag.
Many flexible bulk bags are manufactured from woven plastic fabric or other plastics of a flexible and sturdy nature. One particular problem with these types of flexible bags is that when they become wet, the contents of the bag can become contaminated through the seams or stitches which hold the various parts of the bag together. Thus, although the woven or plastic fabric itself may be impermeable, problems arise when the woven plastic fabric is joined along seams or stitches. Particularly when seams or stitches are formed on the bottom surface of the bulk bag, contamination can occur because the bulk bag will make contact with the ground. Seams or stitches along the bottom surface of the bag may reduce the overall strength of the bag. Over time, the seams can deteriorate due to moisture or other environmental conditions. Even if adhesive or heat sealing is used to join sections of fabric along a bottom surface, these methods of attachment can also deteriorate over time due to material stresses experienced by the bottom surface.